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Preventing biodeterioration of chrome-tanned leather due to mold growth during storage is critical in the leather industry. In this paper, Differential Scanning Calorimeter (DSC), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), Liquid Chromatography-Mass Spectrometry (LC-MS) and characteristic components analysis were used to analyze the biodeterioration process and mechanism of the chrome-tanned leather. Feasible strategies to improve the biodeterioration prevention effect were explored in detail from the aspect of tanning-basification processes and the selection of fungicides. The results showed that molds grow and reproduce by using the available proteins, fats and carbohydrates in the chrome-tanned leather as nutrient resources, metabolizing and secreting alkaline substances such as histamine and spermine, and proteases, simultaneously. The macromolecular organic matter was hydrolyzed into small molecular substances and provided nutrients for microorganisms, meanwhile, the increase of environmental pH caused the dechroming of tanned collagen fiber, accelerating the degradation of collagen fiber, making tanned leather more easily destroyed. Furthermore, the use of a proper amount of MgO for basification was not likely to cause a continuous increase in the pH of the chrome-tanned leather during storage, and the pH of the leather eventually stabilized at about 4.0 during long-term storage. Additionally, the use of 100 mg/L of fungicides MIT, CMIT, IPBC and OIT can effectively kill molds and continuously inhibit the development of mold spores during the storage procedure, which is an effective way to solve biodeterioration of chrome-tanned leather. Hence, this study provides theoretical support for effectively solving the problem of biodegradation of chrome-tanned leather caused by mold growth and reproduction, which could reduce the hazard to the environment while reducing the production cost of tanneries and improving the economic benefits. • Molds decompose collagen and other organic substances in chrome-tanned leather for their growth and reproduction. • Molds metabolize alkaline bioamines to cause the dechroming of chrome-tanned collagen. • Molds metabolize enzymes to accelerate the biodeterioration process. • The use of MgO for basification is not likely to cause a continuous increase in the pH value. • Fungicides MIT, CMIT, IPBC and OIT can effectively kill molds and inhibit the development of mold spores. [ABSTRACT FROM AUTHOR]

Biodeterioration is known to cause irreversible damage to open-air cultural heritages. China has numerous open-air cultural heritages constructed of stone and brick, but very little information is available about the factors involved in their biodeterioration. In this study, different kinds of open-air cultural heritages (steles, towers, temples, Tang-ling carvings, and stone bridges) from 14 different locations in temperate climate zone of China were collected and investigated. Microbiological characteristics of these cultural heritages revealed that both cyanobacteria and lichens were the mainly dominant groups on these open-air stone and brick cultural heritages with visible deterioration. Cyanobacteria were closely associated with the severely deteriorated Tang-ling carvings wile lichens were most commonly found on temples and bridges. The main cyanobacteria were Oscillatoria , Pleurocapsa , and Lyngbya , and the dominant lichens were Xanthoria Th. Fr., Lepraria. Ach. and Camellia on the surface of cultural heritage. In addition, the extent of deterioration associated with cyanobacteria exhibited an increasing trend with higher annual mean sunshine intensity, calcite content, and cultural heritage age though not statistically significant. Redundancy analysis indicated that sunshine intensity and the age of the archeological structures were the key factors that significantly affected the biodeterioration of cultural heritages. This study provides more understanding of the microbial community associated with deterioration of open-air cultural heritages situated at the temperate climate zone of China. • Various open-air cultural heritage elements from Northwest China were collected. • The bioreceptivity characteristics of cultural heritage monuments were investigated. • The biodeterioration were mainly caused by cyanobacteria and lichens. • Sunshine intensity, age, and calcite content obviously affected the bioreceptivity. [ABSTRACT FROM AUTHOR]